The radiochemistry core provides the radiopharmaceuticals necessary to fulfill the goals of the projects described in this grant. The specific aims are to produce O-15, C-11, and F-18 and to use these radionuclides to prepare radiopharmaceuticals:[O-15]H2O, [C-11]CO, [C-11]HCN, [C- 11]CH3I,[C-11]CH2O, 2-[C-11]-thymidine, 1-[C-11] glucose and 6-[F-18]-2- fluorodeoxyglucose, [F-18]fluoromisonidazole and [F-18]fluoroestradiol. In addition, Ge-68/Ga-68 sources are prepared for attenuation scans and calibration standards. Robot-assisted syntheses are used to make procedures more convenient and to keep radiation exposure to the chemists as low as reasonably achievable. The radiochemistry group is responsible for assuring the radiochemical purity and pharmaceutical quality of all products for in vivo studies and for compliance with all regulations regarding radiation safety.